[black_powder_Rob]

How much velocity would be lost going from a 7' barrel to a 6 1/2' barrel. I was looking at getting either the colt navy, or a remington new army police (both are in 36). just curious.

[arcticap]

I don't think that you would lose much measurable velocity at all.
Every powder has a different velocity curve and the type of powder isn't specified.
Also, Colts generally have slightly loser tolerences that allows them to be shot more times with less fouling trouble (especially with the .44's), so they have a tendency to also develop slightly less velocity from the same amount of powder anyway.
Every maker's gun and model could also have slightly different tolerances which may very well negate the small difference in barrel lengths.
Two or 3 grains of powder could more than make up for any difference in velocity, especially since you probably wouldn't be shooting maximum loads to obtain the best accuracy from either revolver.
Any difference then becomes theoretical and only academic.
What if the difference was 25 feet per second? Then what?
You could just as easily switch to a more potent powder.
I did thoroughly enjoy answering the question though! :D
Please, let us know which model you end up buying. :)

[black_powder_Rob]

good answer, Thanks :)

[Wildfire]

Hey There;
I would say you got an excellent answer. I have found about 50fps MAX per inch of barrel. that is a Max figure. 1/2" shorter barrel you might see 25fps less. Maybe.......